Not applicable.
The invention relates to medical devices, and more particularly to minimally invasive surgical systems.
Medical devices configured for minimally invasive surgery are rapidly becoming the tools of choice for many surgical procedures. Not only do these devices provide an alternative-to more invasive surgical tools and procedures, but they have also fostered the development of entirely new procedures.
Devices including highly flexible catheters, as well as rigid and semi-flexible probes have received increased attention in recent years and continue to be refined for cardiovascular, pulmonary, urogenital, and other applications. Devices for each of these applications present different technology and material challenges. Angioplasty catheters, for example, can require fluid-tight passages or channels for circulating a cooling fluid (liquid or gas) through a catheter to cool an electro-surgical structure, such as radio frequency ablation electrode, to prevent overheating of the electrode or of surrounding tissue. Similarly, a cooling or cryogenic fluid can be reduce the temperature of a structure, such as an ablation surface, to a therapeutic temperature. Some cooling fluids, however, can be harmful or fatal to the patient if they unintentionally escape from the surgical device.
Although careful fabrication techniques, quality materials, and thorough testing can reduce the chances of cooling fluid leakage, it would be desirable to provide additional system features that further minimize the occurrence of leaks; and should a leak occur, provide features that detect cooling fluid loss or escape immediately so that use of the surgical device can be terminated and patient remediation efforts can be undertaken if required.
The present invention provides an improved surgical device including a device body defining a sealed fluid path having a first end and a second end, a refrigerant supply in communication with the first end of the sealed fluid path, and a vacuum source in communication with the second end of the sealed fluid path. Leak detection apparatus can be provided in communication with the sealed fluid path.
Exemplary leak detection apparatus include an impedance measurement circuit, an infrared sensor, and a pulsed ultrasonic device. A control unit that is in communication with the leak detection apparatus is responsive to output from the leak detection apparatus to control fluid flow through the sealed fluid flow path.